A detailed histopathological study of the injured spinal cord will be carried out Newly-devised light microscopical methods for enzyme histochemistry will be used. Also a special approach will be employed to distinguish regenerating dorsal root fibers from intraspinal axons. Procedures will be used to promote regeneration by treating the injured cord with various enzymes and by implanting nerve grafts between the cut ends. The effects of spinal transection will be compared with that of spinal hemisection. The possibility of trophic influences in the CNS will be investigated.